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Figure 5.1 |
Illustration of how positive and negative voltage can be used to transmit bits across a wire. In this example, the sender applies a negative voltage to send a 1 bit or a positive voltage to send a 0 bit. |
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Figure 5.2 |
The voltage on a wire as a character is transmitted using RS-232. A start bit notifies the receiver that a character is starting, and each bit transmission lasts the same length of time. |
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Figure 5.3 |
The minimal wiring required for full-duplex RS-232 communication in which control wires are omitted. Although the two circuits carry data independently, it is possible for them to share a single ground wire. |
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Figure 5.4 |
An illustration of the voltage emitted by a real device as it transmits a bit. In practice, voltages are often worse than this example. |
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Photo 1_001 |
Modem showing RS-232 connector |
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Photo 1_010 |
Serial cable to RS-232 connector |
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Photo 1_012 |
Dial-up voice line modem showing RS-232 connector. |
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Photo 1_014 |
RS-232 connectors, showing wiring for three-wire connection |
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Photo 1_024 |
RS-232 connector with control and data wiring |
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Photo 1_025 |
RS-232 connector with control and data wiring |
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Photo 1_037 |
RS-232 cable, showing wiring for RS-232 data and control signals. |
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Photo 1_038 |
RS-232 cable, showing wiring for RS-232 data and control signals. |
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Photo 1_048 |
An RS-232 cable tester |
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Photo 2_020 |
A serial connection switch that interconnects RS-232 serial cables |
